Action And Clinical Pharmacology: Dimethyl sulfoxide has a wide spectrum of primary pharmacologic activity including: membrane penetrant, solute carrier across membranes, anti-inflammatory, analgesia, diuresis, cholinesterase inhibition, muscle relaxation, vasodilation, penetrant of blood-brain barrier. Although the mode of action of dimethyl sulfoxide as a treatment for various inflammatory genitourinary disorders is speculative at this time, hypotheses centre around the following: anti-inflammation, analgesic, improvement of blood supply, softening of collagen due to action on cross linking.
Dimethyl sulfoxide is metabolized by oxidation to dimethyl sulfone or by the reduction to dimethyl sulfide. Dimethyl sulfoxide and dimethyl sulfone are excreted in the urine and feces. Dimethyl sulfide is eliminated through the breath and skin and is responsible for the characteristic odor exuded from patients. The drug can persist in serum for more than 2 weeks after a single intravesical instillation. No residual accumulation of dimethyl sulfoxide has occurred in patients who have received treatment for protracted periods of time. Following topical application dimethyl sulfoxide is absorbed and generally distributed in the tissues and body fluids.
Indications And Clinical Uses: The symptomatic relief of chronic inflammatory genitourinary disorders (cystitis, interstitial cystitis, radiation cystitis, trigonitis and prostatitis).
Contra-Indications: None known.
Manufacturers’ Warnings In Clinical States: Dimethyl sulfoxide has not been approved as being safe and effective for indications other than those listed. There is no clinical evidence of effectiveness in the treatment of bacterial infections of the urinary tract.
Dimethyl sulfoxide can initiate the liberation of histamine and occasional hypersensitivity reactions have occurred with topical administration. Hypersensitivity has not occurred in patients receiving intravesical dimethyl sulfoxide; however, the physician should be cognizant of this possibility.
If anaphylactoid symptoms develop, appropriate therapy should be instituted. Some data indicate that dimethyl sulfoxide potentiates other concomitantly administered medications.
Precautions: Changes in the refractive index and lens opacities have been seen in animals with chronic administration. No ophthalmic changes attributable to intravesical instillation have been reported in patients carefully followed for up to 17 months; however, full eye evaluations, including slit lamp examinations are recommended prior to and at 6 month intervals during treatment.
Patients should be investigated with respect to biochemical parameters, particularly renal and hepatic function, at 6 month intervals.
Intravesical instillation may be harmful to patients with urinary tract malignancy due to dimethyl sulfoxide induced vasodilation.
Pregnancy: Intraperitoneally administered high doses have caused teratogenic responses in animal studies. Oral or topical doses did not cause fetal abnormalities. The safety of dimethyl sulfoxide in the human fetus has not been established and it should be given to pregnant women only when the potential benefits to the mother have been weighed against possible hazards to the child.
Lactation: Although data are lacking, it must be assumed that dimethyl sulfoxide is excreted in human milk. Mothers receiving dimethyl sulfoxide should not nurse their infants.
Adverse Reactions: A garlic like taste may be noted by the patient within a few minutes after instillation. This taste may last several hours and because of the presence of metabolites, an odor on the breath and skin may remain for 72 hours. Transient chemical cystitis has been noted following instillation of 100% dimethyl sulfoxide. The patient may experience moderately severe discomfort on administration. Usually this becomes less prominent with repeated administration.
Dosage And Administration: Adults: For the treatment of chronic inflammatory genitourinary disorders, instill 50 mL of solution directly into the bladder by a catheter or asepto syringe and allow to remain for 15 minutes. For patients with prostatitis, a catheter should be passed gently to the level of the membranous urethra and the medication slowly instilled directly into the prostatic urethra and then into the bladder. Application of an analgesic lubricant gel such as lidocaine jelly to the urethra is suggested prior to insertion of the catheter to avoid spasm. The medication is expelled by spontaneous voiding. It is recommended that the treatment be repeated every 2 weeks until maximum symptomatic relief is obtained. Thereafter, time intervals between therapy may be increased appropriately.
In selected cases where symptomatic relief is not complete, the bladder may be gently distended by gravity instillation with up to 500 mL of a dimethyl sulfoxide solution (one part dimethyl sulfoxide to one part sterile water) prepared in a glass delivery container immediately prior to the procedure. After retention the solution is expelled. Discard any remaining solution. A standard dose of 50 mL of dimethyl sulfoxide should then be instilled for an additional 15 minutes, followed again by expulsion.
Administration of oral analgesic medication or suppositories containing belladonna and opium prior to the instillation of dimethyl sulfoxide can reduce bladder spasm.
In patients with severe bladder symptoms and sensitive bladders, the initial treatment, and possibly the second and third (depending on patient response) should be done under anesthesia (saddle block has been suggested).
Dimethyl sulfoxide is recommended for bladder instillation only.
Availability And Storage: Each 50 mL cartoned bottle contains: 54 g of sterile and pyrogen free 500 mg/g (50% w/w) dimethyl sulfoxide in a clear, colorless and aqueous solution. Protect from light. Store at controlled room temperature (15 to 30°C). Do not autoclave.
RIMSO®-50 Roberts Dimethyl Sulfoxide Genitourinary Disorders
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